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Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, Room 1000, Portland, OR 97204

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Johnson Creek Report Card

Photo of Johnson Creek

This is a summary of conditions in the Johnson Creek Watershed based on data from the 2015 Watershed Health Index. The scores are a snapshot of conditions across the entire watershed. Conditions can vary in smaller parts of the watershed.
Link to introduction page on the watershed report cards

Learn more about the Johnson Creek
Watershed Program and Projects


Johnson Creek Hydrology Score: D

The city and its partners have worked to improve hydrology in the main stem of Johnson Creek for more than 15 years. Environmental Services has restored more than 16,000 feet of stream bank, and work to restore the floodplain and stream banks continues. The stream connectivity score is fair because most of the creek is free-flowing and long lengths of smaller tributaries are not piped as many streams are in other areas of the city. That’s because of the newer development standards in place as east Portland grew, and recent projects to remove or replace culverts.

 

Johnson Creek
Hydrology Average Score

Hydrology score: 7.3

7.3

What is this?
Effective impervious area
Effective impervious area: 7.5
7.5
What is this?
Stream connectivity
Stream connectivity: 7.1
7.1

Johnson Creek Water Quality Score: C+

Johnson Creek has a poor E. coli bacteria score. Much of the Johnson Creek watershed is outside the Portland city limits, but in Portland Johnson Creek E. coli levels are lower since the city completed the Mid-County Sewer Project. There are E. coli hot spots in the city that are likely related to septic systems outside the city limits. Some studies indicate that animal waste is also a source of E. coli in Johnson Creek.

Within Portland, managing stormwater runoff with green street planters and other approaches that filter pollutants will reduce suspend solids and other pollutants. Allowing more stormwater to soak into the ground will replenish groundwater and put more cool water in the creek to reduce water temperatures. Projects, like at Errol Creek Confluence, that restore native vegetation and protect wetlands, seeps and springs will also improve water quality.

 

Johnson Creek
Water Quality Average Score

Water quality score: 5.1

5.1

What is this? Ammonia-nitrogen Ammonia-nitrogen: 9.8
9.8
What is this?
Dissolved copper
Dissolved copper: 6.9
6.9
What is this?
Dissolved oxygen
Dissolved oxygen: 8.3
8.3
What is this?
E. coli
E. coli: 4.0
4.0
What is this? Temperature Temperature: 1.8
1.8
What is this?
Total mercury
Total mercury: 1.4
1.4
What is this?
Total phosphorus
Total phosphorus: 6.3
6.3
What is this?
Total suspended solids
Total suspended solids: 1.9
1.9

Johnson Creek Habitat Score: C

The watershed has a low score for bank conditions, mainly because of rock armoring installed along 15 miles of creek banks in the 1930s. Culverts on tributary streams affect fish accessibility scores.

In the last 15 years, the city has restored over 150 acres of floodplain area. Continuing projects to reduce flooding and improve water quality and fish habitat will improve several of the habitat scores. The city removes rock armoring as part of these projects. Actions like the Crystal Springs restoration projects will improve fish accessibility.

A relatively high tree canopy score is due to protected forested upland areas in the East Buttes. Street and yard tree planting is important in the many residential and industrial areas with below-average canopy. New plantings in restoration projects (over 200,000 trees and shrubs in recent years) and work on private property by community partners will further improve canopy, riparian and floodplain condition scores in the future, as the vegetation matures.

 

Johnson Creek
Habitat Average Score

Johnson Creek Habitat score: 4.7

4.7

What is this? Bank condition (hardening) Bank condition: 1.8
1.8
What is this? Floodplain condition Floodplain condition: 6.0 6.0
What is this? Large wood Large wood: 2.6
2.6
What is this? Riparian integrity Riparian integrity: 5.6
5.6
What is this?
Stream accessibility  Stream accessibility: 3.6 3.6
What is this? Substrate composition Substrate composition: 6.6  6.6
What is this?
Tree canopy
Tree canopy: 6.9
6.9

Johnson Creek Fish and Wildlife Score: D+Johnson Creek has fairly large numbers of fish, including salmon and other native species. The creek is a prime resource to support recovery of endangered salmon in Portland. But fish in Johnson Creek are relatively small. High stream temperatures and lack of large wood limit the ability of salmon and other native fish to grow and thrive. The result is low scores for fish and aquatic insects. Continued investment in riparian area improvement, floodplain restoration, and culvert removal will improve fish and wildlife abundance.

 

Johnson Creek
Fish and Wildlife Average Score

Johnson Creek Fish and wildlife score: D+

3.7

What is this? Birds Birds: 4.2
4.2
What is this?
Fish
Fish: 2.5
 2.5
What is this?
Macroinvertebrates
Macroinvertebrates: 4.3
 4.3

For more information about what we measure and where these scores come from, visit the About Watershed Report Cards page.

See some of what Environmental Services is doing for healthy rivers and streams on the Explore Portland’s Watersheds map.